Diseases and pests of gladioli
Decrease decorativeness, in some cases, various pests lead to complete death of plants. Leaves, buds and flowers of gladioli gnaw at the scoops of cabbage and mustard, naked slugs. The roots and corms of gladioli are damaged by nutcrackers, grubs, winter scoops, gall nematodes. As a result of damage by these pests, the plants lag behind in growth, turn yellow, wilt and die.
Pests of gladioli
It damages all varieties of gladioli, iris, calendula, daffodil, cloves. The adult insect is small, 1-1.5 mm in size, brown, elongated, with fringed wings, a black head. The larva is light yellow, with red eyes, reaches a length of I mm, at the end of the body there is a tubular process.
Adult thrips overwinter under corms of corms in storage, where at temperatures above 10 ° C they multiply continuously. The female lays eggs in the tissue of the plant. Larvae suck juices from leaves and flowers. Mass multiplication of thrips is observed after bulb planting during the flowering period. One generation develops within 2-3 weeks. Over the season, the pest manages to give several generations. As a result of damage by larvae and adult insects, spots and silver-white dots appear on the leaves, yellowish strokes show traces of skin rupture during egg laying, and black dots show insects.
During the ejection of the flower arrow, thrips concentrate around it. When buds appear, they penetrate inside, damage the flowers, which fade, discolor and dry. In autumn, when the temperature drops, thrips move to the lower parts of the plant.
Before harvesting corms, the bulk of the pests are on the “hemp”. Later they go under the scales of corms. They feed on juice from corms of corms. Damaged tissue areas dry out and form crust-like spots of brown color. Corms become light, sticky, and by the end of storage darken, wrinkle, dry out. In addition to direct harm, thrips carry gladiolus pathogens. The pest in the mass multiplies in hot, dry weather.
- with a high number of thrips, early cutting of plants, until the pests moved to the lower part of the stems,
- destruction of tops and all plant residues after harvesting gladioli, digging the soil,
- disinfection of corms populated by thrips by immersing them in hot water (50 ° C) for 5 minutes or spraying with karbofos solution (2 g per 1 liter of water), then the bulbs are dried and stored,
- during storage periodical examination of corms, when a pest is found, the planting material is poured with chalk or fluffy lime at the rate of 20-30 g per 1 kg of corms, placing populated corms in a paper bag with naphthalene (for 10-15 pieces 3-5 g of the preparation) on 1-1.5 months, then the corms are ventilated and stored as usual (you can use naphthalene only until the sprouts appear),
- rejection of infected corms before planting,
- treatment several times in 7-10 days with 10% malathion (75 g per 10 l of water) during the growing season when damaged plants appear (at the end of June),
- re-planting gladioli on the same site after 3-4 years,
- seeding to the gladioli tagetes, calendula, onion, garlic, which are not damaged by thrips.
Root Onion Mite
It damages bulbous plants: lily, hyacinth, tulip, daffodil, gladiolus corms and dahlia tubers. Adult tick up to 1.1 mm long, short-oval, light yellow, shiny.
Ticks live in the soil on plant debris and populate plants planted in the ground. They penetrate the bulbs through the bottom or mechanical damage and settle between the flakes. Females lay eggs on the bulbs. Hatching after 4-7 days from eggs, larvae suck juice from bulb scales and develop within a month. As a result of tick nutrition, plant growth slows down, leaves turn yellow and wilt. The mite damages the bulbs and tubers during storage, especially if they are not cleaned of old scales and roots.
During storage, with severe damage to the bulbs, the outer surface of the scales is covered with brownish dust. Bulbs rot and dry, become rotten. When the bulbs and tubers populated by the mite are planted in the soil, the soil and other plants become infected. The pest is very demanding on high temperature (18 ... 20 ° C) and humidity (more than 60%).
- planting uninfected material in open ground and culling during the growing season of plants with yellowing leaves;
- on infected tick sites, one should not plant bulbous plants and dahlias for 3-4 years;
- collection and destruction of plant debris after harvesting bulbs;
- rejection of healthy bulbs and tubers before laying them for storage, cleaning them of old scales and roots, pouring with chalk or sulfur (20 g per 1 kg of planting material), regular sorting and removal of damaged bulbs, storage at a temperature of 2 ... 5 ° C and air humidity no more than 60%;
- heat treatment for 5 minutes of infected bulbs in water heated to 50 ° C, or 5-7 days at a temperature of 35 ... 40 ° C, disinfection for 30-50 minutes in solutions of Celtan (3 g per 1 liter of water), 30 % malathion (5 g per 1 liter of water);
- spraying with 10% karbofos (75 g per 10 l of water) or watering under the root with 20% celtan (20 g per 10 l of water) during the growing season of plants.
The drying out, or yellowness, of gladioli
It develops with great harmfulness in all places of cultivation of gladioli and throughout the growing season. The roots and corms of gladioli are affected. In this case, there are 2 types of disease: withering and rot of corms. When wilted, the plants turn yellow, starting from the top, twist and die due to browning and dying of the roots.
In the second type of disease, light brown or dark depressed spots form on the corms. On the cross-section of the affected parts of the plants, a turning of the vascular system is visible. Infected corms do not tolerate long-term storage, rot. When planting, they sprout weakly or do not germinate at all, rot in the soil. The infection is transmitted with planting material. The mushroom hibernates in the affected corms and in the soil.
- destruction of diseased plants during the growing season and when digging corms;
- the alternation of cultures with the return of gladioli to their former place after 3-4 years;
- sorting corms before storage and before planting;
- storage in well-ventilated places
- fertilizing plants with magnesium during the growing season;
- digging out holes in the gladioli of patients with corms and filling them with garlic infusion (30 g of infusion per 1 liter of water), filling the holes with earth, and after 5 days processing with a mustard solution;
- soaking before planting corms of gladioli for 8-10 hours in the infusion of marigolds (dry plants are chopped, fill half of the enamelled bucket with them, fill them with warm water and leave for two days), after throwing the peduncles and the beginning of flowering - triple watering with the same infusion.
Corms, leaves, stems, flower petals are affected. Small spots with reddish-brown bordering form on the leaves. In the presence of a large number of spots, the entire sheet turns brown and dies prematurely.
Rounded spots with a reddish-brown border are formed on the affected stems of various sizes. On flower petals, watery spots, merging, lead to the death of the whole flower. Brown spots also form on peduncles. With high air humidity, spots on the leaves, stems, peduncles and flower petals are covered with a gray fluffy coating of the fungus. Sometimes leaves without the formation of spots suddenly turn yellow and die. This happens when the root of the plant is affected.
The defeat of the corm begins with the stem end and is manifested in the browning of the core of the corm. Gradually, the entire inner part of the corms is covered in brown rot. Outwardly, there are no signs of the disease, and only by clicking on the bottom, we can establish that the corm is already rotted. Mushroom overwinters in affected corms and on leaves near the surface of the soil.
- the return of gladioli to their original place no earlier than 4 years later;
- drying corms at a temperature of 25 ... 30 ° C and good ventilation (immediately after digging); rejection of sebaceous corms;
- storage of corms at a temperature of 6 ° C and relative humidity of 75-80%;
- etching the corms before planting in open ground in a solution of potassium permanganate (30 g per 10 l of water) for 1-2 hours, the kids are soaked in a solution of drinking soda (50 g per 10 l of water);
- removal of yellowed and lagging plants (especially during flowering);
- spraying gladioli with a 1% Bordeaux mixture (100 g of vitriol with the addition of 100 g of lime per 10 l of water) after mass flowering or infusions of plants described in measures to combat the drying of gladioli.
Dry rot of stems and corms
Roots, corms, leaves, stems are affected. The first signs appear in the yellowing and browning of the top of the leaves. With the development of the disease, yellowing and death of the entire plant occur to a large extent. On yellowed leaves, roots, corms, at the base of leaves, stems, rounded black bile ducts (sclerotia) form. Affected corms in warehouses are mummified. Mushroom overwinters in affected corms, on plant debris, in soil, where it can remain viable for up to 4 years. Losses from the disease can be from 15 to 50%.
- culling sick corms and planting healthy corms in areas where gladioli have not been planted in the last 4 years;
- drying the corms at a temperature of 25 ... 30 ° C with good ventilation immediately after digging them, etching the corms freed from the scales with potassium permanganate solution (15-30 g per 10 l of water) with an exposure in the solution for 1-2 hours;
- spraying with a 1% Bordeaux mixture (100 g of copper sulfate with the addition of 100 g of lime per 10 l of water) after mass flowering;
- digging the soil with a turnover of the reservoir in the fall;
- recovery of corms: diseased bulbs, not cutting lesions, planted in horse manure; transplanted seedlings into beds without adding manure to the grooves (a certain amount of it is carried along with corms on the roots, watering and loosening is carried out every other day).
Leaves, corms are affected. Rounded light brown spots with dark bordering are formed on the leaves, on which black dots subsequently appear - pycnids containing fungal spores. On corms, the disease develops in the fall in the form of small watery, more or less rounded reddish-brown spots. The spots gradually increase, and their central part becomes submerged, acquires an almost black color and more defined angular outlines. Separate spots merge among themselves.
The affected tissues harden and mummify during storage, which is why the disease is called hard rot. The infection persists in the soil, on affected corms up to 4 years. Infection of plants occurs through the soil. In the growing season from plant to plant, the fungus is distributed by spores that are carried by wind, rain, insects.
The disease is especially harmful in damp, cool years on poor soils.
- the same as with dry rot of gladioli.
The disease is dangerous for dahlias, roses, carnations, gladioli, peonies. The root system of plants is affected. When digging corms in the places of the formation of children, or on the resulting children, rough growths of irregular shape are clearly visible.
- destruction of diseased corms;
- disinfecting the soil in the fall after digging up plants with dry bleach (150-200 g / m2) and filling it with a rake,
- when caring for plants, avoid damage, especially the root system and the root neck,
- planting corms of gladioli is not performed for 2-3 years in areas where foci of cancer are found.
Mosaic of gladioli
Viral disease. Leaves and flowers are affected. On the leaves, spots and annular or angular stripes of yellowish-green and grayish color are formed, located between the leaf veins. Sometimes spots are presented in the form of closed rings. On the flowers, the spots are yellowish-green and gray, and can be in the form of strokes. Because of spots and strokes, the flowers become variegated; their petals sometimes twist.
In diseased plants, the flowers are small, and the flower arrows are greatly increased in length. The development process to the formation of a flower arrow in sick plants is delayed. Sick corms fade from year to year, stop giving a flower arrow. The disease is carried by thrips, aphids. During the growing season, the virus is transmitted from corms to children.
- removal and burning of diseased plants with corms;
- timely destruction of insects - carriers of the virus (aphids, thrips);
- creating optimal conditions for growing gladioli: timely loosening of the soil, weeding, fertilizing;
- planting corms in well-ventilated areas.
Plant protection in household plots - Pearl A. A., Stepanina N. P., Tarasova V. P.